The present invention relates generally to power generation equipment, and more particularly to improved fluid passages for solid oxide fuel cells.
A high temperature, solid oxide fuel cell stack is typically comprises planar cross flow fuel cells, counterflow fuel cells and parallel flow fuel cells that are constructed from flat single cell members and associated with fuel and air distribution equipment. Such members typically comprise trilayer anode/electrolyte/cathode components which conduct current from cell to cell and comprise at least one interconnect having channels for gas flow into a cubic structure or stack.
Solid oxide fuel cells generate electrical energy through electrochemical reactions between an oxidant and hydrocarbon fuel gas to produce a flow of electrons in an external circuit. In addition, solid oxide fuel cells generate waste heat that is typically removed via an oxidant in order to maintain a desired temperature level of solid oxide fuel cell components such as the anode, cathode and electrolyte.
While solid oxide fuel cells have demonstrated the potential for high efficiency and low pollution in power generation, some problems remain associated with temperature regulation of the components in solid oxide fuel cells. Solid oxide fuel cells typically comprise cooling channels in which the oxidant, typically air, is used to aid in the transfer or removal of the waste heat so as to maintain the stack temperature at or below prescribed limits and maintain a predetermined thermal gradient in the solid oxide fuel cell. In some designs, such cooling channels typically comprise smooth straight channels that have an undesired characteristic of providing low thermal transfer coefficients between the channel surface and the oxidant.
Accordingly, there is a need in the art for a solid oxide fuel cell having improved fluid passages that provide improved heat transfer characteristics.